It is has long been known that the grain size of a material has a substantial effect on its mechanical strength, through the
well-established Hall-Petch relationship. In the past decade or so, there has been a resurgence of interest in this topic
resulting from the ability to create metals with grain sizes in the deep sub-micron to nano-crystalline scale via a variety of
processing techniques. In these materials, it has been conjectured that it may no longer be possible to deform individual grains via simple unit dislocation processes, and other mechanisms may be required to achieve plastic flow.

In this tutorial, I will present a brief overview of the ways that transmission electron microscopy can be used to characterize nanoscale materials. This tutorial will emphasize what TEM does well, as well where difficulties arise. In particular, I will discuss in an overview manner how diffraction, imaging and spectroscopy function in the TEM, and how these techniques can be combined to provide a detailed characterization of nanoscale structures. Some emphasis on sample preparation requirements, image artifacts and low sampling statistics will be detailed as well. I hope that at the end of this brief tutorial, you will have a better sense as to when the TEM might help you answer particular questions in your research.

This tutorial presents a broad overview of the basic physical principles of techniques used in scanning electron microscopy (SEM), as well as their application to understanding processing/structure/property relationships in nanostructured materials. Special emphasis is placed on the capabilities (existing and planned) in the microscopy labs of the Birck Nanotechnology Center at Purdue University.